Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Aug. 31, 2013	May 31, 2013
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	100,000	100,000
Common stock, shares issued	28,056	27,996
Common stock, shares outstanding	28,056	27,996